Update & Persist Unit level stat type

[ThePieBandit]

Followon to #10

This enhancement will treat the selection at the top of the page as the "default" stats, but allow you to override at the unit level. This will be per table, and persisted in local storage

Use cases:

• Most of my units do not have limit break expansion, but some TM ones do, as well as One Legend. Those units should use Limit Break Expansion stats, but the default should be the normal limit break
• I put ATK and HP CC on Snakeman, so I don't want to see his bonus to RCV with CC